19 Dec 2022 | 11:08 AM UTC
US: Adverse weather forecast across parts of Hawaii through at least Dec. 20
Severe weather forecast across Hawaii, US, through at least Dec. 20. Transport, business, and utility disruptions possible.
Event
A storm system is forecast to bring severe weather across much of Hawaii through at least Dec. 20. The weather system will bring strong winds, rough seas, heavy rainfall, thunderstorms, and snowfall over higher ground. Heavy downpours could trigger flooding in low-lying areas and landslides on unstable slopes. Strong winds could cause wind damage and power outages, as well as generate rough seas. As of early Dec. 19, the National Weather Service (NWS) has issued high wind warnings and flood watches across Hawaii. Winter storm warnings are in place for elevated areas of Big Island, as well as high surf and gale warnings for coastal areas and offshore waters. A short-term special weather statement for strong thunderstorms has also been issued for Niihau in Kauai and Kauai in Kauai counties. Authorities will likely issue new alerts or update/rescind existing advisories as weather conditions change over the coming days.
Authorities in Maui have opened emergency shelters at Kamalii Elementary School, 180 Alanui Kealii Drive, Kihei, and War Memorial Stadium Complex, 700 Halia Nakoa Street, Wailuku, due to the forecast adverse weather conditions. Some national parks and attractions are closed as of Dec. 19. A section of Highway 270 was closed as of late Dec. 18 due to flooding and debris on the road. Waipio Valley Access Road has also been closed by authorities.
Hazardous Conditions
Where precipitation falls as rain, flash and areal flooding is possible. Such flooding is possible in low-lying communities near watercourses and other large bodies of water and in urban areas with easily overwhelmed stormwater drainage systems. Sites located downstream of large reservoirs may be subject to flash flooding after relatively short periods of intense rainfall.
Precipitation could fall as snow in higher elevations over the coming days. Wind gusts could cause blowing and drifting snow; decreased visibility is likely in mountainous areas. Rain-induced landslides cannot be discounted in areas of elevated terrain. Power outages could occur throughout the affected area.
Transport
Floodwaters and related debris may render some bridges or roadways impassable, impacting overland travel throughout Hawaii. Flooding in urban areas could also result in significant traffic congestion. Heavy snow will likely make driving hazardous in some areas; authorities could implement temporary road closures or detours in such locations. Mountain passes and tunnels could be closed as a precautionary measure during periods of intense snowfall.
The disruptive weather will likely cause some delays and cancellations at regional airports. Authorities may temporarily suspend port operations if strong winds trigger hazardous sea conditions, impacting freight and passenger maritime traffic.
Advice
Monitor local media for weather-related updates and advisories. Confirm all transport reservations and business arrangements before traveling in Hawaii. Seek updated information on road conditions before driving or routing shipments through areas where severe weather is forecast; plan for possible supply chain disruptions throughout the affected areas. Stay away from elevated streams, creeks, and other watercourses that are prone to flash flooding. Do not attempt to navigate flooded roadways. Exercise caution in elevated terrain due to the threat of landslides and mountainous regions where avalanches pose a threat. Charge battery-powered devices in the case of prolonged electricity outages.
